Abrasive tools and methods for forming same

ABSTRACT

An abrasive tool including a bonded abrasive including a body comprising abrasive particles contained within a three-dimensional matrix of bond material, the bond material including an organic material, the abrasive tool further including a first filler contained within the three-dimensional matrix of bond material including a silicate in a first content and a second filler contained within the three-dimensional matrix of bond material including a sulfate in a second content, and the first content is greater than the second content.

FIELD OF THE DISCLOSURE

The present invention relates in general to abrasive tools and, inparticular, to a bonded abrasive.

DESCRIPTION OF RELATED ART

Bonded abrasive articles can be prepared by blending abrasive grainswith a bond and optional additives and shaping the resulting mixture,using, for instance, a suitable mold. The mixture can be shaped to forma green body which can be thermally processed, for example, by curing,to produce an article in which the abrasive grains are held in a threedimensional bond matrix. Among bonded abrasive tools, various bondmatrix materials exist, including for example organic materials, such asresin. A need for improved abrasive articles continues to exist.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example and are not limited in theaccompanying figures.

FIG. 1 includes a cross-sectional view of an abrasive tool in accordancewith an embodiment described herein.

FIG. 2 includes a cross-sectional view of a portion of an abrasive toolin accordance with an embodiment.

FIG. 3 includes a top down view of an abrasive tool according to anembodiment.

FIG. 4 includes a top down view of an abrasive tool according to anembodiment.

FIG. 5 includes a histogram of grinding ratio of abrasive tool sampleshaving different compositions.

FIG. 6A includes an image of a filler having a certain aspect ratioaccording to an embodiment.

FIG. 6B includes an image of a filler having an aspect ratio accordingto an embodiment.

FIG. 6C includes an image of a filler having an aspect ratio accordingto an embodiment.

FIG. 7 includes a histogram of grinding ratio of abrasive tool samples.

FIG. 8 includes a histogram of grinding ratio of abrasive tool samples.

Skilled artisans appreciate that elements in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the elements in the figures maybe exaggerated relative to other elements to help to improveunderstanding of embodiments of the invention.

DETAILED DESCRIPTION

Embodiments disclosed herein are related to abrasive tools including abonded abrasive that may include one or more abrasive regions. Theabrasive tools may be in the form of thin wheels, utilized for grinding,cutting, and general material removal operations. The bonded abrasivecan include a body including abrasive particles contained within a bondmaterial. In an embodiment, the barrier layer can be bonded to a majorsurface of the body.

FIG. 1 includes a cross-sectional illustration of a portion of anabrasive tool according to an embodiment. The abrasive tool 10 caninclude a body including a rear (top) face 12 and a front (bottom) face14. In certain instances, such as illustrated in FIG. 1, the abrasivetool can have a rear face 12 that may include a raised hub region 16 andouter flat rear wheel region 18. The front face 14 can include adepressed center region 20 and outer flat front wheel region 22. Inturn, raised hub region 16 can have raised hub surface 24 and backsloping (or slanted) surface 26; depressed center region 20 can includedepressed center 28 and front sloping (or slanted) surface 30. The bodyof the abrasive tool 10 can have central opening 32 for mounting theabrasive tool 10 on the rotating spindle of a tool, e.g., a hand-heldangle grinder. During operation, the abrasive tool 10 can be secured bymounting hardware such as, for instance, a suitable flange system. Theabrasive tool 10 can also be part of an integrated arrangement thatincludes mounting hardware.

The abrasive tools of the embodiments herein can include any suitabletype of abrasive wheel as known in the art, including thin disc shapedabrasive articles. For example, the abrasive tool can be a depressedcenter wheel, such as, for example, ANSI (American National StandardsInstitute) Type 27, Type 28 or Type 29 wheels, or European Standard (EN14312) Type 42 wheel. In particular embodiments, the abrasive tool mayinclude a Type 41 or Type 1 wheel, which may be referred to as straightwheels, having no depression in the interior but having the same contourand extending along the same plane along the length of the diameter ofthe wheel. Still, essentially any bonded abrasive wheel construction maybe utilized with the present embodiments. Moreover, the abrasive toolsmay be in the form of cut-off wheels.

The body of the abrasive tool 10 can have a thickness “t” that can bemeasured at various positions, including at the periphery of the bondedabrasive body. The thickness (t) of the body of the abrasive tool 10 canbe the same or essentially the same along a radial direction from thecentral opening 36 to the outer edge (periphery) 38 of the abrasive tool10. In other designs, the thickness (t) of the body can vary (canincrease or decrease) along a radial distance from the central opening36 to the periphery 38. Reference herein to a thickness can be referenceto an average thickness of the abrasive tool 10. For example, the bodyof the abrasive tool 10 can have a thickness (t) of not greater than 10mm, such as not greater than 9.5 mm or not greater than 9 mm or notgreater than 8.5 mm or not greater than 8 mm or not greater than 7.5 mmor not greater than 7 mm or not greater than 6.5 mm or not greater than6 mm or not greater than 5.5 mm or not greater than 5 mm or not greaterthan 4.5 mm or not greater than 4 mm. Still, in at least onenon-limiting embodiment, the thickness (t) of the abrasive tool 10 canbe at least 0.3 mm, such as at least 0.5 mm or at least 0.8 mm or atleast 1 mm or at least 1.3 mm or even at least 1.5 mm. It will beappreciated that the body of the abrasive tool 10 can have a thickness(t) within a range including any of the minimum and maximum values notedabove, including for example, within a range including at least 0.3 mmto not greater than 10 mm, such as within a range including at least 0.3mm to not greater than 9 mm, or even within range including at least 0.5mm to not greater than 8 mm.

Further, the body of the abrasive tool 10 of the embodiments herein caninclude a diameter (d), which defines the length of extending betweentwo points on the perimeter and through the center of the body. In anon-limiting embodiment, the diameter (d) can be at least 10 mm, such asat least 25 mm or at least 50 mm or at least 55 mm or at least 60 mm orat least 65 mm or at least 70 mm or at least 75 mm or at least 80 mm orat least 90 mm, or even at least 100 mm. In another non-limitingembodiment, the diameter (d) may be not greater than 400 mm, such as notgreater than 350 mm or not greater than 300 mm or not greater than 275mm or not greater than 250 mm, or even not greater than 230 mm. It willbe appreciated that the diameter (d) of the bonded abrasive body can bewithin a range including any of the minimum to maximum values notedabove, for example, within a range including at least mm 10 mm to notgreater than 400 mm, such as within a range including at least 50 mm tonot greater than 300 mm, or even within a range including at least 50 mmto not greater than 230 mm.

The body of the abrasive tool 10 may have a particular aspect ratio,which is a ratio of the diameter (d) of the body to the thickness (t) ofthe body (diameter:thickness) that may facilitate certain abrasiveoperations. For example, the body can have an aspect ratio of at least10:1 or at least 15:1 or at least 20:1 or at least 35:1 or at least 50:1or at least 75:1 or at least 100:1, or even at least 125:1. In otherinstances, the body of the abrasive tool 10 can have an aspect ratio(diameter:thickness) of not greater than 1000:1, such as not greaterthan 800:1 or not greater than 500:1 or not greater than 400:1 or notgreater than 350:1 or not greater than 300:1 or not greater than 250:1,or even not greater than 200:1. The ratio can be within a rangeincluding any of the above minimum and maximum values, such as within arange including at least 10:1 to not greater than 1000:1, such as withina range including at least 10:1 and not greater than 500:1, or evenwithin a range including at least 10:1 and not greater than 200:1.

The abrasive tools of the embodiments herein can have variousconstructions. The abrasive tools of the embodiments herein may bemonolithic articles formed of a single material, having a singleconstruction, having a substantially uniform grade and structurethroughout the volume of the body of the abrasive tool. Alternatively,the body of the embodiments herein can be composite bodies having one ormore elements (e.g., abrasive regions, abrasive layers, reinforcingmembers, etc.), wherein at least two of the elements are different fromeach other based on a characteristic such as, abrasive particle type,content of abrasive particles, porosity type (e.g., closed or open),content of porosity, type of bond material, content of bond material,distribution of abrasive particles, hardness, flexibility, fillercontent, type of filler materials including individual filler materialsand filler compositions as a whole (i.e., taking into account all of thefiller materials, such as a first filler, a second filler, a thirdfiller, and the like), shape of the layer, size (e.g., thickness, width,diameter, circumference, or length) of the layer, construction of thelayer (e.g., solid, woven, non-woven, etc.) and a combination thereof.

FIG. 2 includes a cross-sectional view of a portion of an abrasive toolaccording to an embodiment. As illustrated, the abrasive tool 200 can bea bonded abrasive having a body 201 including a first abrasive region202, which can include abrasive particles 203 contained within athree-dimensional matrix of bond material 204. The first abrasive regionmay also include fillers 205 contained within the bond material 204. Aswill be described herein, in certain embodiments, the fillers 205 caninclude one or more elements or compositions, including for example, aparticular combination of a first filler, a second filler, a thirdfiller, and the like that may define a filler composition for the firstabrasive region 202.

As further illustrated, the body 201 of the abrasive tool 200 caninclude a second abrasive region 207, which can include abrasiveparticles 208 contained within a three-dimensional matrix of bondmaterial 209. The second abrasive region 207 may also include fillers210 contained within the three-dimensional matrix of the bond material209. As noted herein, the first and second abrasive regions 202 and 207can have include the same features or different features, including butnot limited to, abrasive particle type, content of abrasive particles,porosity type (e.g., closed or open), content of porosity, type of bondmaterial, content of bond material, distribution of abrasive particles,hardness, flexibility, filler content, type of filler materialsincluding individual filler materials and filler compositions as a whole(i.e., taking into account all of the filler materials, such as a firstfiller, a second filler, a third filler, and the like), shape of thelayer, size (e.g., thickness, width, diameter, circumference, or length)of the layer, construction of the layer (e.g., solid, woven, non-woven,etc.) and a combination thereof. In at least one embodiment, the firstabrasive region 202 and second abrasive region 207 can be in the form oflayers that are axially spaced apart from each other within the body201. The layers can extend for the entire diameter of the body 201 withthe exception of an arbor hole or opening at the center of the body asdescribed herein. In still other instances, the body of the abrasivetool can be formed such that the first abrasive region and secondabrasive region define distinct annular regions within the body that areradially spaced apart from each other within the body.

According to one embodiment, as illustrated in FIG. 2, the body 201 mayalso include a reinforcing member 206 disposed between the first andsecond abrasive regions 202 and 207. While FIG. 2 depicts a particulararrangement of the first and second abrasive regions 202 and 207relative to each other and relative to the reinforcing member 206, itwill be appreciated that other constructions of the abrasive tool arewithin the scope of the embodiments herein. The abrasive tools mayinclude a plurality of abrasive regions, which may be in the form oflayers, extending for at least a portion of the diameter of the abrasivetool. The plurality of abrasive regions can be separated from each otherby one or more reinforcing members. Additionally, the body 201 caninclude first and second major surfaces 211 and 212, which may generallycorrespond to surface 18 and 22, which can define the exterior surfacesof the body 201. In certain instances, one or more layers of material,including for example, a reinforcing member or paper backing withindicia may be applied to the first and second major surfaces 211 and212 of the body 201.

According to one embodiment, the first abrasive region 202 can includefiller 205, which can include a first filler. The first filler may bedistinct from the abrasive particles with regard to at least one ofaverage particle size, hardness, composition, shape, and the like. Thefirst filler may include a silicate. For example, the first filler mayinclude calcium, and more particularly, may include a calcium silicatecompound. In one instance, the first filler can include an inosilicatecompound, which may be a single chain inosilicate. An inosilicatecompound includes interlocking chains of silicate tetrahedral. Accordingto a particular embodiment, the first filler comprises wollastonite, andmore particularly, can consist essentially of wollastonite (CaSiO₃).Utilization of a first filler may facilitate improved performance of theabrasive tool 200 as the first filler may be configured to providesuitable mechanical reinforcement to the bond material 204. Moreover, inmore particular instances, the first filler can be a reinforcing agentconfigured to reduce the wear and/or fracture of the bond duringgrinding operations.

In certain embodiments, the first filler may have a particular medianparticle size (D50), which may facilitate improved performance of theabrasive tool 10. For example, the first filler can have a medianparticle size of at least 1 micron, such at least 2 microns or at least3 microns or at least 4 microns or at least 5 microns or at least 6microns or at least 7 microns or at least 8 microns or at least 9microns or at least 10 microns or at least 11 microns or at least 12microns, or even at least 13 microns. Still, in another non-limitingembodiment, the first filler can have a median particle size (D50) ofnot greater than 100 microns, such as not greater than 95 microns or notgreater than 90 microns or not greater than 85 microns or not greaterthan 80 microns or not greater than 75 microns or not greater than 70microns or not greater than 65 microns or not greater than 60 microns ornot greater than 55 microns or not greater than 50 microns or notgreater than 45 microns or not greater than 40 microns or not greaterthan 35 microns or not greater than 30 microns or not greater than 25microns. It will be appreciated that the median particle size of thefirst filler can be within a range including any of the minimum andmaximum values noted above. Moreover, in certain instances, reference tothe foregoing median particle size may be reference to a maximumparticle size, depending upon the sieving technique and the shape of thefirst filler particle.

According to one embodiment, the first filler may have a particularshape, which may make it more suitable for use in the abrasive tools ofthe embodiments herein. Furthermore, the shape of the first filler mayfacilitate improved performance of the abrasive tools of the embodimentsherein. According to one embodiment, the first filler can have an aspectratio (length:width) when viewing the first filler using a suitabletwo-dimensional image of at least 1.2:1, such as at least 1.3:1 or atleast 1.4:1 or at least 1.5:1 or at least 1.6:1 or at least 1.7:1 or atleast 1.8:1 or at least 1.9:1 or at least 2:1, or even at least 3:1. Ina further embodiment, the first filler can have an aspect ratio greaterthan 5:1, such as at least 5.5:1 or at least 6:1 or at least 6.5:1 oreven at least 7:1. Still, in one non-limiting embodiment, the firstfiller can have an aspect ratio of not greater than 100:1, such as notgreater than 90:1 or not greater than 80:1 or not greater than 70:1 ornot greater than 60:1 or not greater than 50:1 or not greater than 40:1or not greater than 30:1 or not greater than 20:1. Still, in anothernon-limiting embodiment, the first filler can have an aspect ratio lessthan 15:1, such as not greater than 14.5:1, or not greater than 14:1, ornot greater than 13.5:1, or not greater than 13:1, or not greater thanor not greater than 12:1, or not greater than 11.5:1, or even notgreater than 10:1. It will be appreciated that the aspect ratio of thefirst filler can be within a range including any of the minimum andmaximum ratios noted above. For example, the aspect ratio of the firstfiller can be greater than 5:1 and less than 15:1, such as within arange from at least 5.5:1 to not greater than 14.5:1, or within a rangefrom at least 6:1 to not greater than 13:1, or within a range from atleast 7:1 to not greater than 10:1.

In certain situations, the first filler may be present in a particularcontent that may facilitate improved performance of the abrasive tool.For example, the first filler can be present in the first abrasiveregion 202 in a first content. According to one embodiment, the firstcontent can be at least 0.1 wt % of the total weight of the firstabrasive region 202, such as at least 0.5 wt % or at least 0.8 wt % orat least 1 wt % or at least 1.2 wt % or at least 1.4 wt % or at least1.6 wt % or at least 1.8 wt % or at least 2 wt % or at least 2.2 wt % orat least 2.4 wt % or at least 2.6 wt % or at least 2.8 wt % or at least3 wt % or at least 3.2 wt % or at least 3.4 wt % or at least 3.6 wt % orat least 3.8 wt % or at least 4 wt %, such as at least 4.2 wt % or atleast 4.5 wt % or at least 5 wt %. Still, in another non-limitingembodiment, the first content can be not greater than 19 wt % of thetotal weight of the first abrasive region 202, such as or not greaterthan 18 wt % or not greater than 17 wt % or not greater than 16 wt % ornot greater than 15 wt % or not greater than 14 wt % or not greater than13 wt % or not greater than 12 wt % or not greater than 11 wt % or notgreater than 10 wt % or not greater than 9 wt % or not greater than 8 wt% or not greater than 7.8 wt % or not greater than 7.5 wt % or notgreater than 7 wt % or not greater than 6 wt % or not greater than 5.5wt %, or even not greater than 5 wt %. It will be appreciated that thefirst content can be within a range including any of the minimum andmaximum ratios noted above, including for example, at least 0.2 wt % andnot greater than 20 wt % for a total weight of the first abrasive region202, or within a range including at least 2 wt % and not greater than 12wt %. In a particular example, the first content can be within a rangeincluding at least 2.8 wt % and not greater than 8 wt %.

According to another embodiment, the first abrasive region 202 caninclude a filler 205, which may include a first filler and a secondfiller, wherein the second filler is distinct from the first filler.Provision of a second filler as part of the filler composition of theabrasive tool may facilitate improved performance. Some suitableexamples of fillers that may be used as a second filler can includepowders, granules, spheres, fibers, or a combination thereof. In anotherembodiment, the second filler can include an inorganic material, anorganic material, or a combination thereof. For example, suitablefillers for use as the second filler can include sand, silicon carbide,bubble alumina, bauxite, chromites, magnesite, dolomites, bubblemullite, borides, titanium dioxide, carbon products (e.g., carbon black,coke or graphite), wood flour, clay, talc, hexagonal boron nitride,molybdenum disulfide, feldspar, nepheline syenite, glass fibers, glassspheres, chlorides (e.g., MgCl₂ and CaCl₂), fluorides (e.g., CaF₂,KBF₄), cryolite (Na₃AlF₆), potassium cryolite (K₃AlF₆), pyrites, ZnS,copper sulfide, mineral oil, carbonates, calcium carbonate, sulphates,dechlorane, and a combination thereof. In a further embodiment, thesecond filler can include an antistatic agent, a metal oxide, alubricant, a porosity inducer, a coloring agent, or a combinationthereof. Examples of the lubricants can include stearic acid, glycerolmonostearate, graphite, carbon, molybdenum disulfide, wax beads, calciumcarbonate, calcium fluoride, or any combination thereof. Examples of themetal oxides can include lime, zinc oxide, magnesium oxide, or anycombination thereof. Note that the second filler may be functional, suchas, grinding aids, lubricants, and porosity inducers. In alternativeinstances, the second filler can be used for functional and/oraesthetics, such as a coloring agent. According to an embodiment, thesecond filler can be distinct from the abrasive particles, includingprimary abrasive particles and secondary abrasive particles. In oneparticular embodiment, the second filler can include a sulfate. In moreparticular instances, the second filler can include potassium, and maybe a compound including potassium. For one particular embodiment, thesecond filler may include a potassium sulfate compound, and even moreparticularly, may consist essentially of potassium sulfate.

In one embodiment, the second filler may have a particular medianparticle size (D50), which may facilitate improved performance of theabrasive tool. For example, the second filler can have a median particlesize of at least 0.1 microns, such at least 0.5 microns or at least 1micron or at least 1.5 microns or at least 2 microns, or even at least 5microns. Still, in another non-limiting embodiment, the second fillercan have a median particle size (D50) of not greater than 500 microns,such as not greater than 450 microns or not greater than 400 microns ornot greater than 350 microns or not greater than 300 microns or notgreater than 275 microns or not greater than 250 microns or not greaterthan 200 microns or not greater than 175 microns or not greater than 150microns, or even not greater than 100 microns. It will be appreciatedthat the median particle size of the second filler can be within a rangeincluding any of the minimum and maximum values noted above. Moreover,in certain instances, reference to the foregoing median particle sizemay be reference to a maximum particle size, depending upon the sievingtechnique and the shape of the second filler particle.

In certain instances, the second filler may have a particular aspectratio (length:width), which may facilitate improved performance of theabrasive tool. The second filler may have an aspect ratio that issubstantially the same as the aspect ratio of the first filler. Still,in at least one other embodiment, the second filler can have an aspectratio that is different compared to the aspect ratio of the firstfiller. For example, the second filler can have an aspect ratio(length:width) when viewing the second filler using a suitabletwo-dimensional image of at least 1.1:1, such as at least 1.3:1 or atleast 1.4:1 or at least 1.5:1 or at least 1.6:1 or at least 1.7:1 or atleast 1.8:1 or at least 1.9:1, or even at least 2:1. Still, in onenon-limiting embodiment, the second filler can have an aspect ratio ofnot greater than 100:1, such as not greater than 90:1 or not greaterthan 80:1 or not greater than 70:1 or not greater than 60:1 or notgreater than 50:1 or not greater than 40:1 or not greater than 30:1 ornot greater than 20:1, or not greater than 10:1 or not greater than 5:1,or even not greater than 2:1. In at least one embodiment, the secondfiller may be substantially equiaxed having an aspect ratio ofapproximately 1:1. It will be appreciated that the aspect ratio of thesecond filler can be within a range including any of the minimum andmaximum ratios noted above.

In certain situations, the second filler may be present in a particularcontent that may facilitate improved performance of the abrasive tool.For example, the second filler can be present in the first abrasiveregion 202 in a second content. According to one embodiment, the secondcontent can be at least 0.01 wt % of the total weight of the firstabrasive region 202, such as at least 0.1 wt % or at least 0.5 wt % orat least 0.8 wt % or at least 1 wt % or at least 1.2 wt % or at least1.4 wt % or at least 1.6 wt % or at least 1.8 wt % or at least 2 wt %,or even at least 2.2 wt %. Still, in another non-limiting embodiment,the second content can be not greater than 15 wt % of the total weightof the first abrasive region 202, such as not greater than 14 wt % ornot greater than 13 wt % or not greater than 12 wt % or not greater than11 wt % or not greater than 10 wt % or not greater than 9 wt % or notgreater than 8 wt % or not greater than 7 wt % or not greater than 6 wt% or not greater than 5 wt % or not greater than 4.5 wt % or not greaterthan 4 wt % or not greater than 3.5 wt % or not greater than 3 wt % ornot greater than 2.8 wt % or not greater than 2.5 wt %, or even notgreater than 2.2 wt %. It will be appreciated that the second contentcan be within a range including any of the minimum and maximum ratiosnoted above, including for example, at least 0.01 wt % and not greaterthan 15 wt % for a total weight of the first abrasive region 202, orwithin a range including at least 1 wt % and not greater than 4 wt %, orwithin a range including at least 1.5 wt % and not greater than 2.5 wt%.

The first abrasive region 202 may utilize particular contents of thefirst filler and second filler with respect to each other, which mayfacilitate improved operation of the abrasive tool 200. In certaininstances, the first content of the first filler and second content ofthe second filler can be substantially the same with respect to eachother. In still other instances, the first content of the first fillerand second content of the second filler can be different with respect toeach other. According to one embodiment, the first abrasive region 202can include a ratio (C1:C2) of the first content (C1) to the secondcontent (C2) as measured in wt % of the first filler and second filler,respectively. According to one embodiment, the first abrasive region 202can have a ratio (C1:C2) of at least 1.1:1, such as at least 1.2:1 or atleast 1.3:1 or at least 1.4:1 or at least 1.5:1 or at least 1.6:1 or atleast 1.7:1 or at least 1.8:1 or at least 1.9:1 or at least 2.1:1 or atleast 2.4:1 or even at least 2.5:1. Still, in a non-limiting embodiment,the first abrasive region 202 can have a ratio (C1:C2) of the firstcontent (C1) to the second content (C2) of not greater than 100:1, suchas not greater than 90:1 or not greater than 80:1 or not greater than70:1 or not greater than 60:1 or not greater than 50:1 or not greaterthan 40:1 or not greater than 30:1 or not greater than 20:1 or notgreater than 10:1 or not greater than 8:1 or not greater than 6:1 or notgreater than 5:1 or not greater than 4:1 or not greater than 3.9:1 ornot greater than 3.5:1 or not greater than 3.2:1 or not greater than 3:1or even not greater than 2.5:1. It will be appreciated that the ratio(C1:C2) can be within a range including any of the minimum and maximumratios noted above, including for example, at least 1.5:1 and notgreater than 3.5:1, or within a range including at least 2.4:1 and notgreater than 3.2:1.

According to another embodiment, the first abrasive region 202 caninclude a filler 205, which may include a first filler and a thirdfiller, wherein the third filler can be distinct from the first filler.Provision of a third filler as part of the filler composition of theabrasive tool may facilitate improved performance. Note that referenceherein to a third filler does not necessitate the inclusion of a secondfiller, but reference to third filler is a convention to distinguish onefiller (e.g., first filler) from another filler (e.g., the thirdfiller). Some suitable examples of fillers that may be used as a thirdfiller can include powders, granules, spheres, fibers, or a combinationthereof. In another embodiment, the third filler can include aninorganic material, an organic material, or a combination thereof. Forexample, suitable materials for use as the third fillers can includesand, silicon carbide, bubble alumina, bauxite, chromites, magnesite,dolomites, bubble mullite, borides, titanium dioxide, carbon products(e.g., carbon black, coke or graphite), wood flour, clay, talc,hexagonal boron nitride, molybdenum disulfide, feldspar, nephelinesyenite, glass fibers, glass spheres, chlorides (e.g., MgCl₂ and CaCl₂),fluorides (e.g., CaF₂, KBF₄), cryolite (Na₃AlF₆), potassium cryolite(K₃AlF₆), pyrites, ZnS, copper sulfide, mineral oil, carbonates, calciumcarbonate, sulphates, dechlorane, and a combination thereof. In afurther embodiment, the third filler can include an antistatic agent, ametal oxide, a lubricant, a porosity inducer, a coloring agent, or acombination thereof. Examples of the lubricants can include stearicacid, glycerol monostearate, graphite, carbon, molybdenum disulfide, waxbeads, calcium carbonate, calcium fluoride, or any combination thereof.Examples of the metal oxides can include lime, zinc oxide, magnesiumoxide, or any combination thereof. Note that the third filler may befunctional, such as, grinding aids, lubricants, and porosity inducers.In alternative instances, the third filler can be used for functionaland/or aesthetics, such as a coloring agent. According to an embodiment,the third filler can be distinct from the abrasive particles, includingprimary abrasive particles and secondary abrasive particles. In at leastone embodiment, the third filler can include a halide-containingcompound. In more particular instances, the third filler can includesodium. Moreover, the third filler may include aluminum. In oneparticular embodiment, the third filler can include sodiumhexafluoroaluminate (Na₃AlF₆) and more particularly, can consistessentially of hexafluoroaluminate (Na₃AlF₆).

In one embodiment, the third filler may have a particular medianparticle size (D50), which may facilitate improved performance of theabrasive tool. For example, the third filler can have a median particlesize of at least 0.1 microns, such at least 0.5 microns or at least 1micron or at least 1.5 microns or at least 2 microns, or even at least 5microns. Still, in another non-limiting embodiment, the third filler canhave a median particle size (D50) of not greater than 500 microns, suchas not greater than 200 microns or not greater than 100 microns or notgreater than 90 microns or not greater than 80 microns or not greaterthan 70 microns or not greater than 60 microns or not greater than 50microns or not greater than 40 microns or even not greater than 30microns. It will be appreciated that the median particle size of thethird filler can be within a range including any of the minimum andmaximum values noted above. Moreover, in certain instances, reference tothe foregoing median particle size may be reference to a maximumparticle size, depending upon the sieving technique and the shape of thethird filler particle.

In certain instances, the third filler may have a particular aspectratio (length:width), which may facilitate improved performance of theabrasive tool. The third filler may have an aspect ratio that issubstantially the same as the aspect ratio of the first filler and/orsecond filler. Still, in at least one other embodiment, the third fillercan have an aspect ratio that is different compared to the aspect ratioof the first filler and/or second filler. For example, the third fillercan have an aspect ratio (length:width) when viewing the second fillerusing a suitable two-dimensional image of at least 1.1:1, such as atleast 1.3:1 or at least 1.4:1 or at least 1.5:1 or at least 1.6:1 or atleast 1.7:1 or at least 1.8:1 or at least 1.9:1, or even at least 2:1.Still, in one non-limiting embodiment, the third filler can have anaspect ratio of not greater than 100:1, such as not greater than 90:1 ornot greater than 80:1 or not greater than 70:1 or not greater than 60:1or not greater than 60:1 or not greater than 50:1 or not greater than40:1 or not greater than 30:1 or not greater than 20:1, or not greaterthan 10:1 or not greater than 5:1, or even not greater than 2:1. In atleast one embodiment, the third filler may be substantially equiaxedhaving an aspect ratio of approximately 1:1. It will be appreciated thatthe aspect ratio of the third filler can be within a range including anyof the minimum and maximum ratios noted above.

In certain situations, the third filler may be present in a particularcontent that may facilitate improved performance of the abrasive tool.For example, the third filler can be present in the first abrasiveregion 202 in a third content. According to one embodiment, the thirdcontent can be at least 0.01 wt % of the total weight of the firstabrasive region 202, such as at least 0.1 wt % or at least 0.5 wt % orat least 0.8 wt % or at least 1 wt % or at least 1.2 wt % or at least1.4 wt % or at least 1.6 wt % or at least 1.8 wt % or at least 2 wt %,or even at least 2.2 wt % or at least 2.4 wt % or at least 2.6 wt % orat least 2.8 wt % or at least 3 wt % or at least 3.1 wt % or at least3.2 wt %. Still, in another non-limiting embodiment, the third contentcan be not greater than 18 wt % of the total weight of the firstabrasive region 202, such as not greater than 17 wt % or not greaterthan 16 wt % or not greater than 15 wt % or not greater than 14 wt % ornot greater than 13 wt % or not greater than 12 wt % or not greater than11 wt % or not greater than 10 wt % or not greater than 9 wt % or notgreater than 8 wt % or not greater than 7 wt % or not greater than 6 wt%, not greater than 5 wt % or not greater than 4 wt % or even notgreater than 3.5 wt %. It will be appreciated that the third content canbe within a range including any of the minimum and maximum ratios notedabove, including for example, at least 0.01 wt % and not greater than 18wt % for a total weight of the first abrasive region 202, or within arange including at least 2.6 wt % and not greater than 4 wt %.

The first abrasive region 202 may utilize particular contents of thefirst filler and third filler with respect to each other, which mayfacilitate improved operation of the abrasive tool. In certaininstances, the first content of the first filler and third content ofthe third filler can be substantially the same with respect to eachother. In still other instances, the first content of the first fillerand third content of the third filler can be different with respect toeach other. For example, according to an embodiment, the third contentof the third filler may be greater than the first content of the firstfiller, or in another instance, the third content of the third fillermay be smaller than the first content of the first filler. According toone embodiment, the first abrasive region 202 can include a ratio(C1:C3) of the first content (C1) to the third content (C3) as measuredin wt % of the first filler and third filler, respectively. According toone embodiment, the first abrasive region 202 can have a ratio (C1:C3)of at least 1.1:1, such as at least 1.2:1 or at least 1.3:1 or at least1.4:1 or at least 1.5:1 or at least 1.6:1 or at least 1.7:1 or at least1.8:1 or at least 1.9:1 or even at least 2:1. Still, in a non-limitingembodiment, the first abrasive region 202 can have a ratio (C1:C3) ofthe first content (C1) to the third content (C3) of not greater than100:1, such as not greater than 90:1 or not greater than 80:1 or notgreater than 70:1 or not greater than 60:1 or not greater than 50:1 ornot greater than 40:1 or not greater than 30:1 or not greater than 20:1or not greater than 10:1 or not greater than 8:1 or not greater than 6:1or not greater than 5:1 or not greater than 4:1 or not greater than 3:1or not greater than 2.5:1 or not greater than 2.2:1 or even not greaterthan 1.9:1. It will be appreciated that the ratio (C1:C3) can be withina range including any of the minimum and maximum ratios noted above, forinstant including at least 1.1:1 and not greater than 2.5:1.

Moreover, the first abrasive region 202 may utilize particular contentsof the second filler and third filler with respect to each other, whichmay facilitate improved operation of the abrasive tool. In certaininstances, the second content of the second filler and third content ofthe third filler can be substantially the same with respect to eachother. In still other instances, the second content of the second fillerand third content of the third filler can be different with respect toeach other. According to one embodiment, the first abrasive region 202can include a ratio (C3:C2) of the third content (C2) to the secondcontent (C2) as measured in wt % of the third filler and second filler,respectively. According to one embodiment, the first abrasive region 202can have a ratio (C3:C2) of at least 1.1:1, such as at least 1.2:1 or atleast 1.3:1 or at least 1.4:1 or at least 1.5:1 or at least 1.6:1 or atleast 1.7:1 or at least 1.8:1 or at least 1.9:1 or even at least 2:1.Still, in a non-limiting embodiment, the first abrasive region 202 canhave a ratio (C3:C2) of the third content (C1) to the second content(C2) of not greater than 100:1, such as not greater than 90:1 or notgreater than 80:1 or not greater than 70:1 or not greater than 60:1 ornot greater than 50:1 or not greater than 40:1 or not greater than 30:1or not greater than 20:1 or not greater than 10:1 or not greater than8:1 or not greater than 6:1 or not greater than 5:1 or not greater than4:1 or not greater than 3:1 or not greater than 2.5:1 or even notgreater than 2:1. It will be appreciated that the ratio (C3:C2) can bewithin a range including any of the minimum and maximum ratios notedabove.

It will be appreciated that reference herein to a filler including afirst filler, second filler, and third filler is not to be interpretedas limited to only three fillers. Other filler compositions may beutilized that include more than two or three fillers as noted herein.Still, in at least one embodiment, the abrasive tool 200 may include oneor more abrasive layers consisting essentially of the first filler,second filler, and third filler.

One or more of the filler materials of the embodiments herein caninclude a coating. The coating can overlie at least a portion of thesurfaces of one or more types of fillers (i.e., the first filler, secondfiller, third filler, etc.) contained in the body. The coating can be amaterial distinct from the bond material. In particular instances, thefirst filler comprises a coating, and may be the only filler materialhaving a coating within the body. The coating can be selected from agroup of materials including an inorganic material, an organic material,a resin, an epoxy, or a combination thereof. In one particular instance,the coating can include a silane, and more particularly, may include asilane-based material including a majority content of silane. In somecases, the coating may facilitate improved bonding between the fillerand the bond material, which may facilitate improved performance of theabrasive tool.

According to an embodiment herein, the body 201 can include a firstabrasive region 202 that may have a particular content of bond materialrelative to the content of one of the fillers, which may facilitateimproved performance. For example, the body 201 can have a ratio(Cff/Cb) of at least 0.2, wherein Cff represents a content of the firstfiller (wt %) for the first abrasive region 202 and Cb represents acontent of the bond material (wt %) for the first abrasive region 202.In other instances, the ratio (Cff/Cb) at least 0.22, such as at least0.24 or at least 0.26 or even at least 0.28. Still, in othernon-limiting embodiments, the ratio (Cff/Cb) can be not greater than 1,such as not greater than 0.9 or not greater than 0.8 or not greater than0.7 or not greater than 0.6 or not greater than 0.5 or even not greaterthan 0.4. It will be appreciated that the ratio (Cff/Cb) can be within arange between any of the minimum and maximum values noted above.

The filler, including each of the first filler, second filler, and thirdfiller can be substantially uniformly distributed throughout thethickness (t1) of the first abrasive region 202. In other embodiments,it is contemplated that a non-uniform distribution of the filler may beutilized with respect to the thickness. For example, in certaininstances, the content of the filler in the first abrasive region 202 atthe major surface 211 may be significantly different compared to thecontent of filler at the interface of the first abrasive region 202 andthe reinforcing member 206. The filler content in the first abrasiveregion 202 can define a content gradient that is gradually changingalong the axis defined by the thickness (i.e., the axial direction) ofthe abrasive tool 200.

FIG. 3 includes a top-down view of an abrasive tool according to anembodiment. As illustrated, the abrasive tool 300 includes a body 301that can include a bonded abrasive as described herein. The body 301 caninclude an annular region 302 defined between the inner annual edge 305and outer peripheral edge 304. According to one embodiment, at least onefiller, such as the first filler, can be substantially uniformlyradially distributed throughout the entire volume of the bond material.That is, for a given abrasive region within the body 301, the content ofthe filler (e.g., first filler) at the inner annular edge 305 to theouter peripheral edge 304 can be substantially the same in a radialdirection. In one particular embodiment, the body 301 can include anabrasive region wherein the first filler is substantially uniformlyradially distributed throughout the entirety of the first abrasiveregion, which can extend between the inner annular edge 305 to the outerperipheral edge 304. It will be appreciated that such a uniformdistribution can exist for any and all components of the body, includingany and all fillers and the abrasive particles. Moreover, while certainabrasive tools may utilize a substantially uniform radial distributionof at least one filler, it will be appreciated that such uniformity maybe attributed to one or more abrasive layers of the body 301.Furthermore, an abrasive article may utilize at least one filler thathas a substantially uniform radial distribution within one abrasiveregion, and a non-uniform distribution within another, differentabrasive region of the body. The non-uniform distribution may extendaxially (i.e., in the direction of the thickness of the body), radially,or both.

FIG. 4 includes a top-down view of an abrasive tool according to anembodiment. As illustrated, the abrasive tool 400 can have a body 401that can include a bonded abrasive as described herein. As illustrated,the body 401 may include different annular regions, including forexample, an inner annular region 403 including the inner annular edge405 of the body 401, which may define the opening 406. The body 401 mayalso include an outer annular region 402 including the outer peripheraledge 404 of the body 401. It will be appreciated that the inner annularregion 403 and outer annular region 402 can be any size and shape assuitable for forming and function of the abrasive tool 400.

According to one embodiment, at least one filler (e.g., the firstfiller) can have a difference in content (wt %) in the inner annularregion 403 compared to the outer annular region 402. For example, incertain instances, the inner annular region 403 can have a differentcontent (wt %) of at least one filler (e.g., the first filler) comparedto the content (wt %) of the same filler in the outer annular region402. In a more particular embodiment, the content of at least onefiller, such as the first filler, can be greater in the outer annularregion 402 compared to the content of the same filler (e.g., the firstfiller) in the inner annular region 403. In yet another embodiment, thecontent of a filler, such as the first filler can be less in the outerannular region 402 compared to the content of the same filler in theinner annular region 403.

According to an embodiment, any one of the abrasive regions of the bodycan have one or more annular regions, including an inner annular regionand outer annular region as illustrated in FIG. 4. Moreover, the body ofan abrasive tool may utilize multiple abrasive regions, wherein each ofthe abrasive regions may have the same arrangement of one or moreannular regions or a different arrangement of one or more annularregions compared to each other. According to one embodiment, the body ofthe abrasive tool can have a first abrasive region and a second abrasiveregion distinct from the first abrasive region, wherein the firstabrasive region and the second abrasive region have at least one of 1) afirst content of abrasive particles in the first abrasive regiondifferent than a second content of abrasive particles in the secondabrasive region or 2) a first type of abrasive particles in the firstabrasive region different than a second type of abrasive particles inthe second abrasive region or 3) a first content of the first filler inthe first abrasive region different than a first content of the firstfiller in the second abrasive region or 4) a first filler composition inthe first abrasive region different than a second filler composition inthe second abrasive region or 5) a first content of bond material in thefirst abrasive region different than a second content of bond materialin the second abrasive region or 6) a first type of bond material in thefirst abrasive region different than a second type of bond material inthe second abrasive region or 7) a second content of a second filler inthe first abrasive region different than a second content of the secondfiller in the second abrasive region or 8) a third content of a thirdfiller in the first abrasive region different than a third content ofthe third filler in the second abrasive region, or a combinationthereof.

In further reference to certain aspects of the abrasive articles of theembodiments herein, the abrasive particles of the abrasive tool mayinclude inorganic materials, organic materials, naturally occurringmaterials (e.g., minerals), superabrasive materials, synthesizedmaterials (e.g., polycrystalline diamond compacts) or a combinationthereof. Some exemplary abrasive particles can include oxides, carbides(e.g., silicon carbide), carbon-based materials, nitrides, borides,oxycarbides, oxynitrides, oxyborides, agglomerated particles,non-agglomerated particles, shaped abrasive particles, non-shapedabrasive particles, or a combination thereof. In at least oneembodiment, the abrasive particles can include alumina-based abrasiveparticles. As used herein, the term “alumina,” “Al₂O₃” and “aluminumoxide” are used interchangeably. Specific examples of suitablealumina-based abrasive grains that can be employed in the presentinvention include white alundum grain, or pink alundum, mono-crystallinealumina, brown fused alumina, heat-treated alumina, alumina-zirconiaabrasive particles, and a combination thereof.

Other abrasive particles can include seeded or unseeded sintered sol gelalumina, with or without chemical modification, such as rare earthoxides, MgO, and the like can be utilized. In yet another embodiment,the abrasive particles can include silica, zirconia, alumina-zirconia,silicon carbide, garnet, boron-alumina, diamond, cubic boron nitride,aluminum-oxynitride, ceria, titanium dioxide, titanium diboride, boroncarbide, tin oxide, tungsten carbide, titanium carbide, iron oxide,chromia, flint, emery, bauxite, and utilized combination thereof.Furthermore, it will be appreciated that the abrasive particles caninclude a blend of one or more different types of abrasive particles asdescribed herein. In one particular embodiment, the abrasive toolincludes a blend of different types of abrasive particles, including afirst type comprising alumina and a second type including siliconcarbide. The abrasive particles of the embodiments herein can consistessentially of any one or more compositions provided herein.

As noted herein, the abrasive particles can include shaped abrasiveparticles. Shaped abrasive particles can have a well-defined and regulararrangement (i.e., non-random) of edges and sides, thus defining anidentifiable and controlled shape from particle-to-particle. Moreover,shaped abrasive particles are distinct from traditional crushed ornon-shaped abrasive particles as the shaped abrasive particles havesubstantially the same shape with respect to each other, whereintraditional crushed abrasive particles vary significantly in their shapewith respect to each other. For example, a shaped abrasive particle mayhave a polygonal shape as viewed in a plane defined by any twodimensions of length, width, and height (e.g., viewed in a plane definedby a length and a width). Some exemplary polygonal shapes can betriangular, quadrilateral (e.g., rectangular, square, trapezoidal,parallelogram), a pentagon, a hexagon, a heptagon, an octagon, anonagon, a decagon, and the like. Additionally, the shaped abrasiveparticle can have a three-dimensional shape defined by a polyhedralshape, such as a prismatic shape or the like. Further, the shapedabrasive particles may have curved edges and/or surfaces, such that theshaped abrasive particles can have convex, concave, ellipsoidal shapes.Exemplary shaped abrasive particles are disclosed in U.S. Pat. No.8,758,461, which is incorporated herein in its entirety.

The size of abrasive particles can be expressed as a grit size, andcharts showing a relation between a grit size and its correspondingaverage particle size, expressed in microns or inches, are known in theart as are correlations to the corresponding United States StandardSieve (USSS) mesh size. Particle size selection depends upon theapplication or process for which the abrasive tool is intended and mayrange from 10 to 325 as per ANSI grit size designation. Specifically,grit sizes may range from 16 to 120 or 16 to 80.

According to one particular embodiment, the abrasive particles can havean average particle size (D50) of at least 1 micron, such as at least 10microns or at least 20 microns or at least 30 microns or at least 40microns. Still, in another non-limiting embodiment, the abrasiveparticles can have an average particle size of not greater than 2 mm,such as not greater than 1 mm or not greater than 800 microns or notgreater than 600 microns or not greater than 500 microns or not greaterthan 400 microns or not greater than 300 microns or not greater than 280microns or not greater than 250 microns or not greater than 200 microns.It will be appreciated that the abrasive particles can have an averageparticle size within a range including any of the minimum and maximumvalues noted above, including for example, within a range between 1micron and 2 mm, within a range between 10 microns and 1 mm, or evenwithin a range between 20 microns and 200 microns.

In at least one embodiment, an abrasive region of the abrasive tool mayinclude a particular content of abrasive particles, which may facilitateimproved performance. For example, the content of abrasive particles inthe first abrasive region 202 can be at least 1 wt % of the total weightof the first abrasive region 202, such as at least 5 wt % or at least 10wt % or at least 20 wt % or at least 30 wt % or at least 40 wt % or atleast 50 wt % or at least 60 wt % or at least 65wt % or at least 70 wt%. Still, in another non-limiting embodiment, the content of abrasiveparticles in the first abrasive region 202 can be not greater than 90 wt% of the total weight of the first abrasive region 202, such as notgreater than 85 wt % or not greater than 83 wt % or not greater than 80wt % or not greater than 78 wt % or even not greater than 75 wt %. Itwill be appreciated that the content of abrasive particles can be withina range including any of the minimum and maximum ratios noted above,including for example, at least 30 wt % and not greater than 90 wt % fora total weight of the first abrasive region 202.

The bond material of one or more abrasive regions of the abrasive toolcan include an organic material. In specific implementations, the bondmaterial can be a polymeric or resin material, which may be formed intothe finally-formed bond material by curing. An example of an organicbond material that can be employed to fabricate bonded abrasive articlescan include a phenolic resin. Such resins can be obtained bypolymerizing phenols with aldehydes, in particular, formaldehyde,paraformaldehyde or furfural. In addition to phenols, cresols, xylenolsand substituted phenols can be employed. Comparable formaldehyde-freeresins also can be utilized. Examples of other suitable organic bondmaterials include epoxy resins, polyester resins, polyurethanes,polyester, rubber, polyimide, polybenzimidazole, aromatic polyamide,modified phenolic resins (such as: epoxy modified and rubber modifiedresins, or phenolic resin blended with plasticizers, etc.), and soforth, as well as mixtures thereof.

In at least one embodiment, an abrasive region of the abrasive tool mayinclude a particular content of bond material, which may facilitateimproved performance. For example, the content of bond material in thefirst abrasive region 202 can be at least 1 wt % of the total weight ofthe first abrasive region 202, such as at least 5 wt % or at least 10 wt% or at least 12 wt % or at least 13 wt % or at least 14 wt %. Inanother non-limiting embodiment, the content of bond material in thefirst abrasive region can be at least 20 wt %, such as at least 30 wt %or at least 40 wt % or at least 50 wt % or at least 60 wt % or at least65wt % or at least 70 wt %. Still, in another non-limiting embodiment,the content of bond material in the first abrasive region 202 can be notgreater than 90 wt % of the total weight of the first abrasive region202, such as not greater than 85 wt % or not greater than 83 wt % or notgreater than 80 wt % or not greater than 78 wt % or even not greaterthan 75 wt %. In yet another non-limiting embodiment, the content ofbond material may be not greater than 60 wt %, such as not greater than50 wt % or not greater than 40 wt % or not greater than 30 wt % or notgreater than 20 wt % or not greater than 18 wt % or not greater than 16wt %. It will be appreciated that the content of bond material can bewithin a range including any of the minimum and maximum ratios notedabove.

Among phenolic resins, resoles can be obtained by a one-step reactionbetween aqueous formaldehyde and phenol in the presence of an alkalinecatalyst. Novolac resin, also known as a two-stage phenolic resin, canbe produced under acidic conditions and during milling process blendedwith a cross-linking agent, such as hexamethylenetetramine (often alsoreferred to as “hexa”). Exemplary phenolic resins can include resole andnovolac. Resole phenolic resins can be alkaline catalyzed and have aratio of formaldehyde to phenol of greater than or equal to one, such asfrom 1:1 to 3:1. Novolac phenolic resins can be acid catalyzed and havea ratio of formaldehyde to phenol of less than one, such as from 0.5:1to 0.8:1.

The bond material can contain more than one phenolic resin, includingfor example or at least one resole and at least novolac-type phenolicresin. In many cases or at least one phenol-based resin is in liquidform. Suitable combinations of phenolic resins are described, forexample, in U.S. Pat. No. 4,918,116 to Gardziella, et al., the entirecontents of which are incorporated herein by reference.

An epoxy resin can include an aromatic epoxy or an aliphatic epoxy.Aromatic epoxies components include one or more epoxy groups and one ormore aromatic rings. An example aromatic epoxy includes epoxy derivedfrom a polyphenol, e.g., from bisphenols, such as bisphenol A(4,4′-isopropylidenediphenol), bisphenol F(bis[4-hydroxyphenyl]methane), bisphenol S (4,4′-sulfonyldiphenol),4,4′-cyclohexylidenebisphenol, 4,4′-biphenol,4,4′-(9-fluorenylidene)diphenol, or any combination thereof. Thebisphenol can be alkoxylated (e.g., ethoxylated or propoxylated) orhalogenated (e.g., brominated). Examples of bisphenol epoxies includebisphenol diglycidyl ethers, such as diglycidyl ether of Bisphenol A orBisphenol F. A further example of an aromatic epoxy includestriphenylolmethane triglycidyl ether, 1,1,1-tris(p-hydroxyphenyl)ethanetriglycidyl ether, or an aromatic epoxy derived from a monophenol, e.g.,from resorcinol (for example, resorcin diglycidyl ether) or hydroquinone(for example, hydroquinone diglycidyl ether). Another example isnonylphenyl glycidyl ether. In addition, an example of an aromatic epoxyincludes epoxy novolac, for example, phenol epoxy novolac and cresolepoxy novolac. Aliphatic epoxy components have one or more epoxy groupsand are free of aromatic rings. The external phase can include one ormore aliphatic epoxies. An example of an aliphatic epoxy includesglycidyl ether of C2-C30 alkyl; 1,2 epoxy of C3-C30 alkyl; mono ormultiglycidyl ether of an aliphatic alcohol or polyol such as1,4-butanediol, neopentyl glycol, cyclohexane dimethanol, dibromoneopentyl glycol, trimethylol propane, polytetramethylene oxide,polyethylene oxide, polypropylene oxide, glycerol, and alkoxylatedaliphatic alcohols; or polyols. In one embodiment, the aliphatic epoxyincludes one or more cycloaliphatic ring structures. For example, thealiphatic epoxy can have one or more cyclohexene oxide structures, forexample, two cyclohexene oxide structures.

An example of an aliphatic epoxy comprising a ring structure includeshydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol Fdiglycidyl ether, hydrogenated bisphenol S diglycidyl ether,bis(4-hydroxycyclohexyl)methane diglycidyl ether,2,2-bis(4-hydroxycyclohexyl)propane diglycidyl ether,3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate,3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate,di(3,4-epoxycyclohexylmethyl)hexanedioate,di(3,4-epoxy-6methylcyclohexylmethyl) hexanedioate,ethylenebis(3,4-epoxycyclohexanecarboxylate),ethanedioldi(3,4-epoxycyclohexylmethyl) ether, or2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-1,3-dioxane.

An exemplary multifunctional acrylic can include trimethylolpropanetriacrylate, glycerol triacrylate, pentaerythritol triacrylate,methacrylate, dipentaerythritol pentaacrylate, sorbitol triacrylate,sorbital hexacrylate, or any combination thereof. In another example, anacrylic polymer can be formed from a monomer having an alkyl grouphaving from 1-4 carbon atoms, a glycidyl group or a hydroxyalkyl grouphaving from 1-4 carbon atoms. Representative acrylic polymers includepolymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate,polyglycidyl methacrylate, polyhydroxyethyl methacrylate, polymethylacrylate, polyethyl acrylate, polybutyl acrylate, polyglycidyl acrylate,polyhydroxyethyl acrylate and mixtures thereof.

Curing or cross-linking agents that can be utilized depend on thebonding material selected. For curing phenol novolac resins, forinstance, a typical curing agent is hexa. Other amines, e.g., ethylenediamine; ethylene triamine; methyl amines and precursors of curingagents, e.g., ammonium hydroxide which reacts with formaldehyde to formhexa, also can be employed. Suitable amounts of curing agent can bewithin the range, for example, of from 5 to 20 parts, or 8 parts to 15parts, by weight of curing agent per hundred parts of total novolacresin. It will be appreciated that the ratio can be adjusted based onvarious factors, including for example the particular types of resinsused, the degree of cure needed, and the desired final properties forthe articles, such as strength, hardness, and grinding performance.

As noted herein and according to one embodiment, the bonded abrasive canbe reinforced with one or more reinforcing members, which may be in theform of layers, partial layers, discrete bundles of material distributedthroughout the body, and a combination thereof. As used herein, the term“reinforcing member” can refer to a discrete component that can be madeof a material that is different from the bond material and abrasiveparticles utilized to make the abrasive layers within the bondedabrasive body. In an embodiment, the reinforcing member does not includeabrasive particles. With respect to the thickness of the bondedabrasive, a reinforcing member can be embedded within the body of thebonded abrasive and such bonded abrasives may be referred to as“internally” reinforced. A reinforcing member also can be close to, orattached to the front and/or back face of the body of the bondedabrasive. Several reinforcing members can be disposed at various depthsthrough the thickness of the bonded abrasive.

Certain reinforcing members may have a circular geometry. The outerperiphery of the reinforcing member also can have a square, hexagon oranother polygonal geometry. An irregular outer edge also can be used.Suitable non-circular shapes that can be utilized are described in U.S.Pat. Nos. 6,749,496 and 6,942,561, incorporated herein by reference intheir entirety. In certain instances wherein the bonded abrasive is inthe form of a wheel or disc, the reinforcing member can extend from theinner diameter (edge of the central opening) to the outermost edge(i.e., peripheral surface) of the bonded abrasive body. Partialreinforcing members can be employed and in such cases, the reinforcingmember may extend, for example, from the mounting hole to at least 30%along the radius or, for non-circular shapes, along the equivalent ofthe largest “radius” of the bonded abrasive body. For example, a partialreinforcing member can extend for at least 60% or at least 70% or atleast 75% or at least 80% or at least 85% or at least 90% or at least95%, or even at least 99% along the radius or, for non-circular shapes,along the equivalent of the largest “radius” of the body of the bondedabrasive. In another non-limiting embodiment, the partial reinforcingmember may extend for not greater than 100%, such as not greater than99% or not greater than 97% or not greater than 95% or not greater than90% or not greater than 85% or not greater than 80% or not greater than70%, or even not greater than 60% along the radius or the equivalent ofthe largest “radius” of the bonded abrasive body. It will be appreciatedthat the partial reinforcing member can extend within a range includingany of the minimum and maximum values noted above. For instance, thepartial reinforcing member can extend within a range of 60% to 100%,such as, within a range of 70% to 99%, or within a range of 80% to 90%along the radius or the equivalent of the largest “radius” of the bondedabrasive body

The reinforcing member can include various materials, including a singlematerial or more than one type of material, such as a compositematerial. Moreover, the abrasive tool of the embodiments herein can usea single type of reinforcing member or may use different types ofreinforcing members, which can employ different materials with respectto each other. Some suitable reinforcing member materials can includewoven materials or non-woven materials. In at least one embodiment, thereinforcing member can include a glass material, including but notlimited to a fiberglass material. In yet other embodiments, thereinforcing member can include, a fiber (e.g., Kevlar®), basalt, carbon,fabric organic materials (e.g., elastomers, rubbers), combinations ofmaterials and so forth. An exemplary reinforcing member can include apolymeric film (including primed films) including for example, apolyolefin film (e.g., polypropylene including biaxially orientedpolypropylene), a polyester film (e.g., polyethylene terephthalate), apolyamide film, a cellulose ester film, a metal foil, a mesh, a foam(e.g., natural sponge material or polyurethane foam), a cloth (e.g.,cloth made from fibers or yams comprising fiberglass, polyester, nylon,silk, cotton, poly-cotton, or rayon), a paper, a vulcanized paper, avulcanized rubber, a vulcanized fiber, a nonwoven material, or anycombination thereof, or treated versions thereof. A cloth backing can bewoven or stitch bonded. In particular examples, the reinforcing membercan be selected from a group consisting of paper, polymer film, cloth,cotton, poly-cotton, rayon, polyester, poly-nylon, vulcanized rubber,vulcanized fiber, fiberglass fabric, metal foil or any combinationthereof. In other examples, the reinforcing member includes a wovenfiberglass fabric. In a particular example, the bonded abrasive caninclude one more layers of fiberglass between which a blend abrasivegrains or particles are bound in a bond material such as a polymermatrix. Using reinforcing members also can allow for shear at theinterface between the reinforcing member and adjacent region(s) of thebonded abrasive (which contain abrasive grains or particles distributedin a three dimensional bond material matrix). It will be appreciatedthat a reinforcing member can consist essentially of any of theforegoing materials or consists essentially of two or more of theforegoing materials noted above.

In specific examples, the body can include at least one or morefiberglass reinforcing members, provided, for instance, in the form offiberglass web(s). Fiberglass webs can include fiberglass woven fromvery fine fibers of glass. Fiberglass web can include leno or plainwoven. The fiberglass utilized can include E-glass (alumino-borosilicateglass with less than 1 wt % alkali oxides). Other types of fiberglasscan include, for example, A-glass (alkali-lime glass with little or noboron oxide), E-CR-glass (alumino-lime silicate with less than 1 wt %alkali oxides, with high acid resistance), C-glass (alkali-lime glasswith high boron oxide content, used for example for glass staplefibers), D-glass (borosilicate glass with high dielectric constant),R-glass (alumino silicate glass without MgO and CaO with high mechanicalrequirements), or S-glass (alumino silicate glass without CaO but withhigh MgO content with high tensile strength).

Fiberglass webs can be arranged in the bonded abrasive such as a bondedabrasive wheel in any suitable manner. In certain implementations,placement of a glass fiber web at the working face of the wheel may beavoided. Any of the embodiments herein can be reinforced with at leastone fiberglass web having a hole corresponding to the central opening orarbor hole of the wheel and the same diameter as the wheel. Partial webreinforcing members that extend from the mounting hole through some butnot the total radius of the wheel also can be used, as can be other webreinforcement placements.

The abrasive tools of the embodiments herein, with or without one ormore reinforcing members, can be prepared by forming a mixture of thecomponents, including but not limited to abrasive particles, a bondmaterial, e.g., an organic material (resin) or an inorganic material,and in many cases other ingredients, such as, for instance, fillers,processing aids, lubricants, crosslinking agents, antistatic agents andso forth.

The various ingredients can be added in any suitable order and blendedusing known techniques. The resulting mixture can be used to form agreen body. As used herein, the term “green” refers to a body whichmaintains its shape during the next process step, but generally does nothave enough strength to maintain its shape permanently. Green may alsorefer to a body that is unfinished, or that there are further processesyet to be completed before transforming the green body to afinally-formed abrasive tool. For example, a resin bond present in thegreen body is in an uncured or unpolymerized state. The green bodypreferably is molded in the shape of the desired article.

One or more reinforcing members can be incorporated in the green body.For example, a first portion of a mixture can be placed and distributedat the bottom of an appropriate mold cavity and then covered with afirst reinforcing member. A second portion of the mixture can then bedisposed and distributed over the first reinforcing member. Additionalreinforcing members and/or bond/abrasive mixture layers can be provided,if so desired. The amounts of mix added to form a particular layerthickness can be modified as suitable for the intended purposes of theabrasive article. Other suitable sequences and/or techniques can beemployed to shape the reinforced green body. For instance, a piece ofpaper or a fiberglass mesh or web or a piece of paper with a fiber glassmesh or web may be inserted in the mold cavity before the first mixture.

As noted herein, the body can be formed of one or more abrasive regions,which may be in the form of layers, which can have the same or differentcharacteristics, such as, layer thickness, layer formulation (e.g.,amounts and or types of ingredients being employed, grit size, gritshape, porosity), filler materials, bond composition, bond content,abrasive content, abrasive particle composition, porosity, pore size,porosity distribution, porosity type (i.e., closed and/or open porosity)and the like.

The bonded abrasive body described herein can be fabricated to have acertain porosity. The porosity can be set to provide a particularperformance of the abrasive tool, including parameters such as hardness,strength, and initial stiffness, as well as chip clearance and swarfremoval. Porosity can be uniformly or non-uniformly distributedthroughout the body of the bonded abrasive and can be intrinsicporosity, obtained by the arrangement of grains within the bond matrix,shape of the abrasive grains and/or bond precursors being utilized,pressing conditions, curing conditions and so forth, or can be generatedby the use of pore inducers. Both types of porosity can be present.

The porosity can be closed and/or interconnected (open). In “closed”type of porosity, the pores are generally discrete with respect to eachother and are not interconnected. In contrast, “open” porosity presentspores that are interconnected to one another creating an interconnectednetwork of channels.

In one embodiment, an abrasive region of the abrasive tool may containporosity of at least 0.1 vol % for a total volume of the abrasiveregion, such as at least 1 vol % or at least 2 vol % or at least 3 vol %or even at least 5 vol %. In another non-limiting embodiment, theporosity may be not greater than 40 vol %, such as not greater than 35vol % or not greater than 30 vol % or not greater than 25 vol %, or notgreater than 20 vol % or not greater than 15 vol % or not greater than10 vol %, or even not greater than 5 vol % for the total volume ofabrasive layers within the body of the bonded abrasive. It will beappreciated that the porosity of the bonded abrasive can be within arange including any of the minimum and maximum values noted above, suchas within the range of from 1 vol % to 40 vol %.

Various techniques can be used to produce the abrasive tools, includingfor example cold pressing, warm pressing, or hot pressing. In accordancewith a particular embodiment the process of forming the abrasivearticles herein can include cold pressing. In cold pressing, thematerials in the mold are maintained at approximately ambienttemperature, such as less than 30° centigrade (C). Force can be appliedto the materials in the mold. For example, the applied force can be atleast 40 tons. The applied force may be not greater than 2000 tons. Theapplied force can be within a range of 100 tons to 2000 tons.Alternatively, pressure can be applied to the materials by suitablemeans, such as a hydraulic press. The pressure applied can be, forexample, in the range of 4.2 kg/cm2 (60 psi or 0.03 tsi), 8.4 kg/cm2(120 psi or 0.06 tsi) 70.3 kg/cm2 (0.5 tsi) to 2109.3 kg/cm2 (15 tsi),or in the range of 140.6 kg/cm2 (1 tsi) to 843,6 kg/cm2 (6 tsi). Theholding time within the press can be, for example, within the range offrom less than 2.5 seconds to 1 minute.

Wheels may be molded individually or large “bats” can be molded, fromwhich individual wheels are later cored out. The various abrasive mixlayers, which comprise abrasive grain, resin and fillers), fiberglassreinforcement and barrier layer material are sequentially placed into amold cavity in the appropriate configuration. The barrier layer canserve as the outermost layers of the stack. The full stack can bepressed using forces commensurate with the pressures described above.The barrier layer can adhere to the abrasive mixture, and thusultimately be bonded in-situ to the abrasive wheel as a result of thecuring process.

It will be appreciated however that warm pressing or hot pressing may beutilized to form the abrasive articles. Warm pressing and hot pressingare similar to cold pressing operations, except that higher temperaturesmay be utilized during the application of pressure.

In the embodiments employing an organic bond material, the bondedabrasive can be formed by curing the organic bond material. As usedherein, the term “final cure temperature” is the temperature at whichthe molded article is held to effect polymerization, e.g.,cross-linking, of the organic bond material, thereby forming the finalcomposition of the bond material, although cross-linking can begin atlower temperatures. The curing temperature may be utilized during otherprocesses, such as during the cold pressing operation. Alternatively,certain processes of the embodiments herein, can utilize a separatecuring step, which can be separate from other processes such as the coldpressing operation. In such instances, the pressing operation may befirst conducted, and the uncured abrasive article may be removed fromthe press and placed in a temperature-controlled chamber to facilitatecuring. As used herein, “cross-linking” refers to the chemicalreaction(s) that take(s) place in the presence of heat and often in thepresence of a cross-linking agent, such as “hexa” orhexamethylenetetramine, whereby the organic bond composition hardens.Generally, the molded article can be held at a final cure temperaturefor a period of time, such as between 6 hours and 48 hours, between 10and 36 hours, or until the center of mass of the molded article reachesthe cross-linking temperature and desired grinding performance (e.g.,density of the cross-link).

Selection of a curing temperature depends, for instance, on factors suchas the type of bonding material employed, strength, hardness, andgrinding performance desired. According to certain embodiments, thecuring temperature can be in the range including at least 100° C. to notgreater than 250° C. In more specific embodiments employing organicbonds, the curing temperature can be in the range including at least150° C. to not greater than 230° C. Polymerization of novolac-basedresins may occur at a temperature in the range of including at least110° C. and not greater than 225° C. Resole resins can polymerize at atemperature in a range of including at least 100° C. and not greaterthan 225° C. Certain novolac resins suitable for the embodiments hereincan polymerize at a temperature in a range including at least 110° C.and not greater than 250° C.

Items

Item 1. An abrasive tool comprising a bonded abrasive including a bodycomprising abrasive particles contained within a three-dimensionalmatrix of bond material, the bond material comprising an organicmaterial; a first filler contained within the three-dimensional matrixof bond material comprising a silicate in a first content; and a secondfiller contained within the three-dimensional matrix of bond materialcomprising a sulfate in a second content; and wherein the first contentis greater than the second content.

Item 2. An abrasive tool comprising: a bonded abrasive including a bodycomprising: a first abrasive region including abrasive particlescontained within a three-dimensional matrix of bond material, the bondmaterial comprising an organic material, wherein the first abrasiveregion further comprises a first filler comprising a silicate containedwithin the three-dimensional matrix of bond material, wherein the firstfiller is substantially uniformly radially distributed throughout thefirst abrasive region; and a reinforcing member coupled to the firstabrasive region.

Item 3. An abrasive tool comprising: a bonded abrasive including a bodycomprising: a diameter, a thickness, and a ratio of diameter:thicknessof at least about 10:1; and a first abrasive region including abrasiveparticles contained within a three-dimensional matrix of bond materialcomprising an organic material, wherein the first abrasive regionfurther comprises a first filler contained within the three-dimensionalmatrix of bond material comprising a silicate, wherein the first filleris substantially uniformly radially distributed throughout the firstabrasive region.

Item 4. An abrasive tool comprising: a bonded abrasive including a bodycomprising: a first abrasive region including abrasive particlescontained within a three-dimensional matrix of bond material comprisingan organic material, wherein the first abrasive region further comprisesa first filler contained within the three-dimensional matrix of bondmaterial comprising a silicate, the first abrasive region comprising aratio (Cff/Cb) of at least 0.2 and not greater than 1, wherein Cffrepresents a content of the first filler (wt %) for the first abrasiveregion and Cb represents a content of the bond material (wt %) for thefirst abrasive region; and a reinforcing member coupled to the firstabrasive region.

Item 5. An abrasive tool comprising: a bonded abrasive including a bodyhaving a thickness not greater than 10 mm comprising: a first abrasiveregion including abrasive particles contained within a three-dimensionalmatrix of bond material, the bond material comprising an organicmaterial, wherein the first abrasive region further comprises a firstfiller comprising a silicate contained within the three-dimensionalmatrix of bond material, wherein the first filler is substantiallyuniformly radially distributed throughout the first abrasive region, andwherein the first abrasive region comprises a content of wollastonitewithin a range including at least 0.2 wt % and not greater than 20 wt %for a total weight of the first abrasive region.

Item 6. The abrasive tool of any of the items herein, wherein the firstfiller comprises calcium.

Item 7. The abrasive tool of any of the items herein, wherein the firstfiller comprises a calcium silicate compound.

Item 8. The abrasive tool of any of the items herein, wherein the firstfiller comprises an inosilicate compound.

Item 9. The abrasive tool of any of the items herein, wherein the firstfiller comprises wollastonite.

Item 10. The abrasive tool of any of the items herein, wherein the firstfiller consists essentially of wollastonite (CaSiO3).

Item 11. The abrasive tool of any of the items herein, wherein the firstfiller comprises a median particle size (D50) of at least 1 micron or atleast 2 microns or at least 3 microns or at least 4 microns or at least5 microns or at least 6 microns or at least 7 microns or at least 8microns or at least 9 microns or at least 10 microns or at least 11microns or at least 12 microns or at least 13 microns.

Item 12. The abrasive tool of any of the items herein, wherein the firstfiller comprises a median particle size (D50) of not greater than 100microns or not greater than 95 microns or not greater than 90 microns ornot greater than 85 microns or not greater than 80 microns or notgreater than 75 microns or not greater than 7+0 microns or not greaterthan 65 microns or not greater than 60 microns or not greater than 55microns or not greater than 50 microns or not greater than 45 microns ornot greater than 40 microns or not greater than 35 microns or notgreater than 30 microns or not greater than 25 microns.

Item 13. The abrasive tool of any of the items herein, wherein the firstfiller is a material distinct from the abrasive particles.

Item 14. The abrasive tool of any of the items herein, wherein the firstfiller is substantially uniformly distributed throughout the entirevolume of the bond material.

Item 15. The abrasive tool of any of the items herein, wherein the firstcontent of the first filler is substantially the same in an outerannular region of the body as compared to a content of the first fillerin an inner annular region of the body.

Item 16. The abrasive tool of any of the items herein, wherein the firstcontent of the first filler is substantially the same at a peripheraledge of the body as compared to an inner annular edge of the body.

Item 17. The abrasive tool of any of the items herein, wherein the firstfiller is substantially uniformly radially distributed throughout thefirst abrasive region;

Item 18. The abrasive tool of any of the items herein, wherein the firstabrasive region comprises an inner annular region and an outer annularregion, wherein the inner annular region has a different content (wt %)of the first filler compared to a content (wt %) of the first filler inthe outer annular region.

Item 19. The abrasive tool of any of the items herein, wherein thecontent of the first filler is greater in the outer annular regioncompared to the inner annular region.

Item 20. The abrasive tool of any of the items herein, wherein thecontent of the first filler is less in the outer annular region comparedto the inner annular region.

Item 21. The abrasive tool of any of the items herein, wherein the firstfiller is a reinforcing agent configured to reduce the wear of the bondduring grinding operations.

Item 22. The abrasive tool of any of the items herein, wherein the firstfiller is a particle having an aspect ratio of length:width of at least1.1:1.

Item 23. The abrasive tool of any of the items herein, wherein theaspect ratio is at least 1.2:1 or at least 1.3:1 or at least 1.4:1 or atleast 1.5:1 or at least 1.6:1 or at least 1.7:1 or at least 1.8:1 or atleast 1.9:1 or at least 2:1.

Item 24. The abrasive tool of any of the items herein, wherein theaspect ratio is not greater than 100:1 or not greater than 90:1 or notgreater than 80:1 or not greater than 70:1 or not greater than 60:1 ornot greater than 60:1 or not greater than 50:1 or not greater than 40:1or not greater than 30:1 or not greater than 20:1 or not greater than10:1.

Item 25. The abrasive tool of any of the items herein, wherein the bodycomprises a first abrasive region including abrasive particles containedwithin the three-dimensional matrix of bond material and the firstfiller is present in a first content within a range including at least0.2 wt % and not greater than 20 wt % for a total weight of the firstabrasive region.

Item 26. The abrasive tool of any of the items herein, wherein the firstcontent is at least 0.1 wt % of the first abrasive region or at least0.5 wt % or at least 0.8 wt % or at least 1 wt % or at least 1.2 wt % orat least 1.4 wt % or at least 1.6 wt % or at least 1.8 wt % or at least2 wt % or at least 2.2 wt % or at least 2.4 wt % or at least 2.6 wt % orat least 2.8 wt % or at least 3 wt % or at least 3.2 wt % or at least3.4 wt % or at least 3.6 wt % or at least 3.8 wt % or at least 4 wt % orat least 4.2 wt %.

Item 27. The abrasive tool of any of the items herein, wherein the firstcontent is not greater than 19 wt % of the first abrasive region or notgreater than 18 wt % or not greater than 17 wt % or not greater than 16wt % or not greater than 15 wt % or not greater than 14 wt % or notgreater than 13 wt % or not greater than 12 wt % or not greater than 11wt % or not greater than 10 wt % or not greater than 9 wt % or notgreater than 8 wt % or not greater than 7 wt % or not greater than 6 wt% or not greater than 5 wt %.

Item 28. The abrasive tool of any of the items herein, furthercomprising a second filler contained within the three-dimensional matrixof bond material comprising a sulfate in a second content.

Item 29. The abrasive tool of any of the items herein, wherein the firstcontent of the first filler is greater than the second content of thesecond filler.

Item 30. The abrasive tool of any of the items herein, wherein thesecond filler comprises potassium.

Item 31. The abrasive tool of any of the items herein, wherein thesecond filler comprises a potassium sulfate compound.

Item 32. The abrasive tool of any of the items herein, wherein thesecond filler consists essentially of potassium sulfate.

Item 33. The abrasive tool of any of the items herein, wherein thesecond filler comprises an average particle size of at least 0.1microns.

Item 34. The abrasive tool of any of the items herein, wherein thesecond filler comprises an average particle size of not greater than 500microns.

Item 35. The abrasive tool of any of the items herein, wherein thesecond filler is a particle having an aspect ratio of length:width of atleast 1.1:1.

Item 36. The abrasive tool of any of the items herein, wherein thesecond filler has a different aspect ratio (length:width) compared to anaspect ratio (length:width) of the first filler.

Item 37. The abrasive tool of any of the items herein, wherein the bodycomprises a first abrasive region including abrasive particles containedwithin the three-dimensional matrix of bond material and the secondfiller present in the second content within a range including at least0.01 wt % and not greater than 15 wt % for a total weight of the firstabrasive region.

Item 38. The abrasive tool of any of the items herein, wherein thesecond content is at least 0.1 wt % or at least 0.5 wt % or at least 0.8wt % or at least 1 wt % or at least 1.2 wt % or at least 1.4 wt % or atleast 1.6 wt % or at least 1.8 wt % or at least 2 wt % or at least 2.2wt %.

Item 39. The abrasive tool of any of the items herein, wherein thesecond content is not greater than 14 wt % or not greater than 13 wt %or not greater than 12 wt % or not greater than 11 wt % or not greaterthan 10 wt % or not greater than 9 wt % or not greater than 8 wt % ornot greater than 7 wt % or not greater than 6 wt % or not greater than 5wt %.

Item 40. The abrasive tool of any of the items herein, wherein theabrasive region comprises a ratio (C1:C2) of the first content (C1) tothe second content (C2) of at least 1.1:1 or at least 1.2:1 or at least1.3:1 or at least 1.4:1 or at least 1.5:1 or at least 1.6:1 or at least1.7:1 or at least 1.8:1 or at least 1.9:1 or at least 2:1.

Item 41. The abrasive tool of any of the items herein, wherein theabrasive region comprises a ratio (C1:C2) of the first content (C1) tothe second content (C2) of not greater than 100:1 or not greater than90:1 or not greater than 80:1 or not greater than 70:1 or not greaterthan 60:1 or not greater than 60:1 or not greater than 50:1 or notgreater than 40:1 or not greater than 30:1 or not greater than 20:1 ornot greater than 10:1 or not greater than 8:1 or not greater than 6:1 ornot greater than 5:1 or not greater than 4:1 or not greater than 3:1 ornot greater than 2.5:1.

Item 42. The abrasive tool of any of the items herein, furthercomprising a third filler contained within the three-dimensional matrixof bond material comprising a halide-containing compound in a thirdcontent.

Item 43. The abrasive tool of any of the items herein, wherein the firstcontent is greater than the third content.

Item 44. The abrasive tool of any of the items herein, wherein the thirdfiller comprises sodium.

Item 45. The abrasive tool of any of the items herein, wherein the thirdfiller comprises aluminum.

Item 46. The abrasive tool of any of the items herein, wherein the thirdfiller comprises sodium hexafluoroaluminate (Na3AlF6).

Item 47. The abrasive tool of any of the items herein, wherein the thirdfiller consists essentially of sodium hexafluoroaluminate (Na3AlF6).

Item 48. The abrasive tool of any of the items herein, wherein the thirdfiller comprises a median particle size (D50) of at least 1 micron.

Item 49. The abrasive tool of any of the items herein, wherein the thirdfiller comprises an average particle size of not greater than 50microns.

Item 50. The abrasive tool of any of the items herein, wherein the thirdfiller is a particle having a substantially equiaxed shape.

Item 51. The abrasive tool of any of the items herein, wherein the thirdfiller has a substantially elongated shape.

Item 52. The abrasive tool of any of the items herein, wherein the thirdfiller has a different aspect ratio (length:width) compared to an aspectratio (length:width) of the first filler.

Item 53. The abrasive tool of any of the items herein, wherein the thirdfiller has a different aspect ratio (length:width) compared to an aspectratio (length:width) of a second filler.

Item 54. The abrasive tool of any of the items herein, wherein the thirdfiller is present in a third content within a range including at least0.01 wt % and not greater than 18 wt % for a total weight of the firstabrasive region.

Item 55. The abrasive tool of any of the items herein, wherein the thirdcontent is at least 0.1 wt % or at least 0.5 wt % or at least 0.8 wt %or at least 1 wt % or at least 1.2 wt % or at least 1.4 wt % or at least1.6 wt % or at least 1.8 wt % or at least 2 wt % or at least 2.2 wt % orat least or at least 2.4 wt % or at least 2.6 wt % or at least 2.8 wt %or at least 3 wt % or at least 3.2 wt %.

Item 56. The abrasive tool of any of the items herein, wherein the thirdcontent is not greater than 17 wt % or not greater than 16 wt % or notgreater than 15 wt % or not greater than 14 wt % or not greater than 13wt % or not greater than 12 wt % or not greater than 11 wt % or notgreater than 10 wt % or not greater than 9 wt % or not greater than 8 wt% or not greater than 7 wt % or not greater than 6 wt % or not greaterthan 5 wt % or not greater than 4 wt %.

Item 57. The abrasive tool of any of the items herein, wherein theabrasive region comprises a ratio (C1:C3) of the first content (C1) tothe third content (C3) of at least 1.1:1 or at least 1.2:1 or at least1.3:1 or at least 1.4:1 or at least 1.5:1 or at least 1.6:1 or at least1.7:1 or at least 1.8:1 or at least 1.9:1 or at least 2:1.

Item 58. The abrasive tool of any of the items herein, wherein theabrasive region comprises a ratio (C1:C3) of the first content (C1) tothe second content (C2) of not greater than 100:1 or not greater than90:1 or not greater than 80:1 or not greater than 70:1 or not greaterthan 60:1 or not greater than 50:1 or not greater than 40:1 or notgreater than 30:1 or not greater than 20:1 or not greater than 10:1 ornot greater than 5:1 or not greater than 3:1 or not greater than 2.5:1.

Item 59. The abrasive tool of any of the items herein, wherein the firstabrasive region further includes a second filler contained within thethree-dimensional matrix of bond material.

Item 60. The abrasive tool of any of the items herein, wherein thesecond filler present in a second content within a range including atleast 0.01 wt % and not greater than 15 wt % for a total weight of thefirst abrasive region.

Item 61. The abrasive tool of any of the items herein, wherein the firstabrasive region further comprises a third filler in a third content, andwherein the first abrasive region comprises a ratio (C3:C2) of the thirdcontent (C3) to the second content (C2) of at least 1.1:1 or at least1.2:1 or at least 1.3:1 or at least 1.4:1 or at least 1.5:1 or at least1.6:1 or at least 1.7:1 or at least 1.8:1 or at least 1.9:1 or at least2:1.

Item 62. The abrasive tool of any of the items herein, wherein theabrasive region comprises a ratio (C3:C2) of the third content (C3) tothe second content (C2) of not greater than 100:1 or not greater than90:1 or not greater than 80:1 or not greater than 70:1 or not greaterthan 60:1 or not greater than 60:1 or not greater than 50:1 or notgreater than 40:1 or not greater than 30:1 or not greater than 20:1 ornot greater than 10:1 or not greater than 5:1 or not greater than 3:1 ornot greater than 2.5:1.

Item 63. The abrasive tool of any of the items herein, wherein theabrasive particles include a material selected from the group consistingof oxides, nitrides, carbides, carbon-based materials, borides,oxynitrides, oxycarbides, oxyborides, naturally occurring minerals,agglomerated particles, non-agglomerated particles, and a combinationthereof, and wherein the abrasive particles comprise shaped abrasiveparticles, wherein the abrasive particles comprise alumina.

Item 64. The abrasive tool of any of the items herein, wherein theabrasive particles comprise a blend of different types of abrasiveparticles, a first type including alumina and a second type includingsilicon carbide.

Item 65. The abrasive tool of any of the items herein, wherein the bodycomprises a first abrasive region including abrasive particles containedwithin the three-dimensional matrix of bond material, wherein the firstabrasive region includes a content of abrasive particles within a rangeincluding at least 30 wt % and not greater than 90 wt % for a totalweight of the first abrasive region.

Item 66. The abrasive tool of any of the items herein, wherein the bodycomprises at least one reinforcing member extending radially through atleast a portion of the body, wherein the at least one reinforcing layercomprises a material selected from the group consisting of a fabric, afiber, a film, a woven material, a non-woven material, a glass, afiberglass, a ceramic, a polymer, a resin, a polymer, a fluorinatedpolymer, an epoxy resin, a polyester resin, a polyurethane, a polyester,a rubber, a polyimide, a polybenzimidazole, an aromatic polyamide, amodified phenolic resin, and a combination thereof.

Item 67. The abrasive tool of any of the items herein, wherein the bodyincludes a first reinforcing member extending radially through at leasta portion of the body at a first axial position and a second reinforcingmember extending radially through at least a portion of the body at asecond axial position different than the first axial position.

Item 68. The abrasive tool of any of the items herein, wherein the bodycomprises a diameter (D) extending radially across the body and athickness (t) extending axially across the body, wherein the bodycomprises a ratio of diameter:thickness of at least about 10:1 or atleast about 20:1 or at least about 50:1, or at least about 100:1.

Item 69. The abrasive tool of any of the items herein, wherein thethree-dimensional matrix of bond material includes an organic materialselected from the group consisting of a resin, an epoxy, a polymer, anda combination thereof, wherein the bond material comprises a phenolicresin.

Item 70. The abrasive tool of any of the items herein, wherein the bodycomprises a first abrasive region including abrasive particles containedwithin the three-dimensional matrix of bond material, wherein the firstabrasive region includes a content of the three-dimensional matrix ofbond material within a range including at least 1 wt % and not greaterthan 40 wt % for a total weight of the first abrasive region.

Item 71. The abrasive tool of any of the items herein, wherein the bodycomprises a first abrasive region and a second abrasive region distinctfrom the first abrasive region, wherein the first abrasive region andthe second abrasive region comprise at least one of:

-   -   a. a first content of abrasive particles in the first abrasive        region different than a second content of abrasive particles in        the second abrasive region;    -   b. a first type of abrasive particles in the first abrasive        region different than a second type of abrasive particles in the        second abrasive region;    -   c. a first content of the first filler in the first abrasive        region different than a first content of the first filler in the        second abrasive region;    -   d. a first filler composition in the first abrasive region        different than a second filler composition in the second        abrasive region;    -   e. a first content of bond material in the first abrasive region        different than a second content of bond material in the second        abrasive region;    -   f. a first type of bond material in the first abrasive region        different than a second type of bond material in the second        abrasive region;    -   g. a second content of a second filler in the first abrasive        region different than a second content of the second filler in        the second abrasive region;    -   h. a third content of a third filler in the first abrasive        region different than a third content of the third filler in the        second abrasive region;

Item 72. The abrasive tool of any of the items herein, wherein the firstabrasive region and second abrasive region are layers that are axiallyspaced apart from each other within the body.

Item 73. The abrasive tool of any of the items herein, wherein the firstabrasive region and second abrasive region define distinct annularregions within the body that are radially spaced apart from each otherwithin the body.

Item 74. The abrasive tool of any of the items herein, wherein the bodycomprises a thickness not greater than 10 mm or not greater than 9.5 mmor not greater than 9 mm or not greater than 8.5 mm or not greater than8 mm or not greater than 7.5 mm or not greater than 7 mm or not greaterthan 6.5 mm or not greater than 6 mm or not greater than 5.5. mm or notgreater than 5 mm or not greater than 4.5 mm or not greater than 4 mm,and wherein the body comprises a thickness of at least 0.3 mm or atleast 0.5 mm or at least 0.8 mm or at least 1 mm.

Item 75. The abrasive tool of any of the items herein, wherein the firstfiller comprises a coating overlying at least a portion of the surfaceof the first filler, wherein the coating is selected from the groupconsisting of an inorganic material, an organic material, a resin, anepoxy, and a combination thereof.

Item 76. The abrasive tool of any of the items herein, wherein thecoating comprises silane.

Item 77. The abrasive tool of any of the items herein, wherein the firstfiller is a particle having an aspect ratio of length:width greater than5:1.

Item 78. The abrasive tool of any of the items herein, wherein the firstfiller is a particle having an aspect ratio of length:width less than15:1.

Item 79. The abrasive tool of any of the items herein, wherein the firstfiller is a particle having an aspect ratio within a range of greaterthan 5:1 to less than 15:1.

Item 80. The abrasive tool of any of the items herein, wherein the firstfiller is a particle having an aspect ratio within a range of at least7:1 to 10:1.

Item 81. The abrasive tool of any of the items herein, wherein the firstfiller is present in a first content within a range including at least0.2 wt % and not greater than 20 wt % for a total weight of the firstabrasive region.

Item 82. The abrasive tool of any of the items herein, wherein the firstfiller is present in the first content within a range including at least2 wt % and not greater than 12 wt % for a total weight of the firstabrasive region.

Item 83. The abrasive tool of any of the items herein, wherein the firstfiller is present in the first content within a range including at least2.8 wt % and not greater than 8 wt % for a total weight of the firstabrasive region.

Item 84. The abrasive tool of any of the items herein, wherein thesecond content of the second filler is within a range including 1 wt %and not greater than 4 wt % for a total weight of the first abrasiveregion.

Item 85. The abrasive tool of any of the items herein, wherein theabrasive region comprises a ratio (C1:C2) of the first content (C1) tothe second content (C2) of at least 1.5:1 and not greater than 3.5:1.

Item 86. The abrasive tool of any of the items herein, wherein the thirdfiller is present in the third content within a range including at least2.6 wt % and not greater than 4 wt %.

Item 87. The abrasive tool of any of the items herein, wherein theabrasive region comprises a ratio (C1:C3) of the first content (C1) tothe third content (C3) in a range including at least 1.1:1 and notgreater than 2.5:1.

EXAMPLE 1

A representative sample (S1) of an abrasive tool having a depressedcenter shape with an outer diameter of 230 mm, an inner diameter ofapproximately 22 mm, and an average thickness of approximately 6.5-7.5mm was made using the following procedure. A mixture including thecomponents provided in Table 1 was created and provided in a mold.Sample S1 was created to have the construction of a first reinforcingmember of fiberglass (approximately 260 gsm), a first layer of themixture overlying the first reinforcing member, a second reinforcingmember of fiberglass (approximately 320 gsm) overlying the first layer,a second layer of the abrasive mixture overlying the second reinforcingmember, and a third reinforcing member overlying the second layer. Thesample (S1) was cold pressed including application of a pressure withina range of 90-160 bars at approximately room temperature. Then, thesample was cured in an oven at approximately 170-200° C. for at least 8hours.

TABLE 1 Sample S1 Weight % INGREDIENT in mix Brown fused alumina 33.578(approximate average particle size of 1190 microns) SiC (approximate40.932 average particle size of 1035 microns) Resole 3.954 Novolac10.690 Cryolite 3.565 Potassium sulfate 2.403 Wollastonite 4.411 CastorOil 0.199 Titania 0.269

EXAMPLE 2

Mixtures having a conventional composition W1 and compositionsrepresentative of embodiments herein, W2 and W3, were used to formabrasive tool samples in the same manner as described for Sample 51 inExample 1. The compositions are disclosed in Table 2 below. W1 did notinclude wollastonite, the mixture W2 included wollastonite, but hadreduced contents of bond material, resole and novolac, as compared toW1. W3 included wollastonite, had similar contents of resin, butdecreased contents of cryolite and potassium sulfate, as compared to W1.All of the ingredients added up to 100 wt % for each composition. Threesamples for each composition were tested utilizing Bosch 9-inch Anglegrinder on Grey Cast Iron plates having thickness of 15 mm. Grinding wasperformed at an angle of 30 to 45 degrees with 2.4 kW rated power(corresponding to an average of 4 to 6 kg normal force) and controlledcurrent within 8 to 9 Amps. Average G-Ratio and MRR (material removalrate) for each of W2 and W3 compositions was used to compare to theaverage G-Ratio and MRR of W1, respectively. The relative G-Ratio andMRR of W1 is 1.00, respectively, and the relative G-Ratio and MRR of W2and W3 samples are included in FIG. 5. MRR of W2 and W3 was similar tothat of W1. However, W2 demonstrated reduced G-Ratio with relativeG-Ratio of 0.59, while W3 demonstrated increased G-Ratio with relativeG-ratio of 1.36.

TABLE 2 W1 W2 W3 Weight Weight Weight Ingredient % in mix % in mix % inmix Brown fused 33.639 32.821 33.578 alumina SiC 41.006 40.008 40.932Resole 3.961 3.729 3.954 Novolac 10.710 8.701 10.690 Cryolite 5.8035.662 3.565 Potassium sulfate 4.413 4.305 2.403 Wollastonite 0.000 4.3114.411 Castor oil 0.199 0.199 0.199 Titania 0.269 0.263 0.269

EXAMPLE 3

Mixtures having compositions W6, W9, W11, W 12, and W13, as disclosed inTable 3 below, were used to form additional representative abrasive toolsamples. Samples of W1 were also formed. W6, W9, W11, W 12, and W13included Wollastonite having aspect ratios of 7:1, 4:1, 5:1, 10:1, and15:1, respectively. FIGS. 6A to 6C include images of wollastonite havingaspect ratios of 4:1, 7:1, and 10:1, respectively.

TABLE 3 W6 W9 W11 W12 W13 Weight Weight Weight Weight Weight Ingredient% in mix % in mix % in mix % in mix % in mix Brown fused 33.566 33.56633.566 33.566 33.566 alumina SiC 40.917 40.917 40.917 40.917 40.917Resole 3.952 3.952 3.952 3.952 3.952 Novolac 10.686 10.686 10.686 10.68610.686 Cryolite 3.118 3.118 3.118 3.118 3.118 Potassium 2.001 2.0012.001 2.001 2.001 sulfate Wollastonite 5.291 5.291 5.291 5.291 5.291Castor oil 0.199 0.199 0.199 0.199 0.199 Titania 0.269 0.269 0.269 0.2690.269

Three samples for each of the compositions were formed, and all of thesamples were tested utilizing Bosch 9-inch Angle grinder on Grey CastIron plates having thickness of 15 mm. Grinding was performed at anangle of 30 to 45 degrees with 2.4 kW rated power (corresponding to anaverage of 4 to 6 kg normal force) and controlled current within 8 to 9Amps. Average G-Ratio and MRR (material removal rate) for each ofcompositions W6, W9, W11, W 12, and W13 was compared to thecorresponding average of W1 samples. Relative G-Ratio and MRR of W1 is1.00, respectively. Relative performance of G-Ratio and MRR of samplesof W6 and W9 is included in FIG. 7, and FIG. 8 includes relativeperformance for samples W11 to W13. Samples of W1, W6, and W9demonstrated similar MRR. Samples of W9 had G-Ratio that was comparableto W1, while W6 demonstrated improved G-Ratio over W1 and W9. Asdisclosed in FIG. 7, the relative G-Ratio of W6 is 1.6, while therelative G-Ratio of W9 is 1.2. As disclosed in FIG. 8, MRR of samples ofW1 and W11 to W13 were comparable, but G-ratio of W12 was improved overW1, W11, and W13. Samples of W11 and W13 demonstrated similar G-ratio ascompared to W1. The relative G-ratio for W11 to W13 is 1.0, 1.5, and1.0, respectively.

Note that not all of the activities described above in the generaldescription or the examples are required, that a portion of a specificactivity may not be required, and that one or more further activitiesmay be performed in addition to those described. Still further, theorder in which activities are listed is not necessarily the order inwhich they are performed.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

The specification and illustrations of the embodiments described hereinare intended to provide a general understanding of the structure of thevarious embodiments. The specification and illustrations are notintended to serve as an exhaustive and comprehensive description of allof the elements and features of apparatus and systems that use thestructures or methods described herein. Certain features, that are forclarity, described herein in the context of separate embodiments, mayalso be provided in combination in a single embodiment. Conversely,various features that are, for brevity, described in the context of asingle embodiment, may also be provided separately or in a subcombination. Further, reference to values stated in ranges includes eachand every value within that range. Many other embodiments may beapparent to skilled artisans only after reading this specification.Other embodiments may be used and derived from the disclosure, such thata structural substitution, logical substitution, or another change maybe made without departing from the scope of the disclosure. Accordingly,the disclosure is to be regarded as illustrative rather thanrestrictive.

The description in combination with the figures is provided to assist inunderstanding the teachings disclosed herein, is provided to assist indescribing the teachings, and should not be interpreted as a limitationon the scope or applicability of the teachings. However, other teachingscan certainly be used in this application.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a method,article, or apparatus that comprises a list of features is notnecessarily limited only to those features but may include otherfeatures not expressly listed or inherent to such method, article, orapparatus. Further, unless expressly stated to the contrary, “or” refersto an inclusive-or and not to an exclusive-or. For example, a conditionA or B is satisfied by any one of the following: A is true (or present)and B is false (or not present), A is false (or not present) and B istrue (or present), and both A and B are true (or present).

Also, the use of “a” or “an” is employed to describe elements andcomponents described herein. This is done merely for convenience and togive a general sense of the scope of the invention. This descriptionshould be read to include one or at least one and the singular alsoincludes the plural, or vice versa, unless it is clear that it is meantotherwise. For example, when a single item is described herein, morethan one item may be used in place of a single item. Similarly, wheremore than one item is described herein, a single item may be substitutedfor that more than one item.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. The materials, methods, andexamples are illustrative only and not intended to be limiting. To theextent that certain details regarding specific materials and processingacts are not described, such details may include conventionalapproaches, which may be found in reference books and other sourceswithin the manufacturing arts.

1. An abrasive tool comprising: a bonded abrasive including a body comprising a first abrasive region including: abrasive particles contained within a bond material, the bond material comprising an organic material; a first filler contained within the bond material comprising a silicate in a first content; and a second filler contained within the bond material comprising a sulfate in a second content; and wherein the first content is greater than the second content.
 2. The abrasive tool of claim 1, wherein the first filler comprises a calcium silicate compound.
 3. The abrasive tool of claim 2, wherein the first filler comprises wollastonite.
 4. The abrasive tool of claim 1, wherein the first content is within a range including at least 0.2 wt % and not greater than 20 wt % for a total weight of the first abrasive region.
 5. The abrasive tool of claim 4, wherein the first content is within a range including at least 2.8 wt % and not greater than 8 wt % for a total weight of the first abrasive region.
 6. The abrasive tool of claim 1, the second filler comprises a potassium sulfate compound.
 7. The abrasive tool of claim 6, wherein the second filler consists essentially of potassium sulfate.
 8. The abrasive tool of claim 1, wherein the second content of the second filler is within a range including 1 wt % and not greater than 4 wt % for a total weight of the first abrasive region.
 9. The abrasive tool of claim 1, wherein the abrasive region comprises a ratio (C1:C2) of the first content (C1) to the second content (C2) of at least 1.5:1 and not greater than 3.5:1.
 10. The abrasive tool of claim 1, further comprising a third filler contained within the bond material comprising a halide-containing compound in a third content.
 11. The abrasive tool of claim 10, wherein the third filler comprises sodium hexafluoroaluminate (Na₃AlF₆).
 12. The abrasive tool of claim 10, wherein the third filler has a third content of at least 2.6 wt % and not greater than 4 wt %.
 13. The abrasive tool of claim 1, wherein the first filler is a particle having an aspect ratio of length:width within a range including greater than 5:1 and less than 15:1.
 14. The abrasive tool of claim 13, wherein the first filler is a particle having an aspect ratio within a range including at least 7:1 and not greater than 10:1.
 15. An abrasive tool comprising: a bonded abrasive including a body having a thickness not greater than 10 mm comprising: a first abrasive region including abrasive particles contained within a bond material, the bond material comprising an organic material, wherein the first abrasive region comprises a first filler in a first content comprising a silicate contained within the bond material, wherein the first filler is a particle having an aspect ratio of length:width of at least 1.5:1, and a second filler contained within the bond material comprising a sulfate in a second content
 16. The abrasive tool of claim 15, wherein the abrasive region comprises a ratio (C1:C2) of the first content (C1) to the second content (C2) of at least 1.1:1.
 17. The abrasive tool of claim 15, wherein the first filler comprises an inosilicate compound.
 18. The abrasive tool of claim 15, wherein the first filler comprises an aspect ratio within a range including at least 7:1 and not greater than 10:1.
 19. The abrasive tool of claim 15, wherein the second filler comprises a potassium sulfate compound.
 20. The abrasive tool of claim 15, wherein the first abrasive region includes a content of abrasive particles within a range including at least 30 wt % and not greater than 90 wt % for a total weight of the first abrasive region. 